1. Field of the Invention
The present invention relates generally to an optical apparatus for an automotive vehicle, and more specifically to an optical apparatus which can protect various optical elements housed in the optical apparatus for an automotive vehicle from intense sunlight.
2. Description of the Prior Art
Recently, various optical apparatus which transmit light toward the outside or receive light from the outside through a lens or lenses are mounted on an automotive vehicle for various purposes. In these optical apparatus, when intense sunlight is directly or even indirectly applied to the optical elements arranged in the optical apparatus in summer, in particular, there exists a probelm in that the inner optical elements are heated to high temperature and therefore damaged. To overcome this problem, there has been proposed an optical apparatus provided with a shutter for covering the optical path when the intensity of light introduced into the optical apparatus from the outside exceeds a predetermined value. In these prior-art optical apparatus when an ignition key is once turned off or when the vehicle is left parked or in trouble, there still exists a problem in that the protective shutter will not be actuated and therefore the optical elements are damaged by heat.
The arrangements of the prior-art optical apparatus will be described in further detail hereinafter with reference to the attached drawings under DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS.